and aluminum compounds, called quantum wells are nanometers thick, much smaller than the thickness of a hair. Electrons jump from one energy level to another, rather than moving smoothly between levels and tunnel from one layer to the next going "through" rather than "over" energy barriers separating the wells. When the electrons jump, they emit photons of light. The quantum cascade laser was co-invented by Alfred Y. Cho, Claire F. Gmachl, Federico Capasso, Deborah Sivco, Albert Hutchinson, and Alessandro Tredicucci at Bell Laboratories in 1994. On April 4, 1994, the Bell Labs team filed U.S. patent #5,457,709 that was issued on October 10, 1995. 1995 Bose–Einstein condensate A Bose–Einstein condensate (BEC) is a state of matter of bosons confined in an external potential and cooled to temperatures very near to absolute zero (). Satyendra Nath Bose and Albert Einstein first conceptualized BEC in 1924–1925; in 1995 Wolfgang Ketterle at MIT and Eric Cornell and Carl Wieman at the University of Colorado at Boulder National Institute of Standards and Technology Laboratory produced a BEC. 1995 Screenless hammer mill The screenless hammer mill, like regular hammer mills, is used to pound grain. The screenless hammer mill uses air flow to separate small particles from larger ones, rather than a screen, and is thus more reliable which results in much more energy efficiency. The screenless hammer mill was invented in 1995 by MIT professor and engineer Amy B. Smith. 1995 Scroll wheel A scroll wheel (or mouse wheel), a hard plastic or rubbery disc on a computer mouse, is used to scroll a pointer up or down on a computer display. It is perpendicular to the mouse surface and is normally located between the left and right mouse buttons. Eric Michelman invented the scroll wheel at Microsoft by in 1995. On December 16, 1998, Michelman filed the earliest patent for a scroll wheel, U.S. patent #6,940,488, which was later issued to him on September 6, 2005. 1995 JavaScript JavaScript, a scripting language widely used for client-side web development, became the originating dialect of the ECMAScript standard. It is a dynamic, weakly typed, prototype-based language with first-class functions. JavaScript was influenced by many languages and was designed to look like Java, but to be easier for non-programmers to work with. Brendan Eich invented JavaScript (which he called Mocha) in 1995; it later became renamed to LiveScript, and finally to JavaScript. 1996 Adobe Flash Adobe